Field of the Invention
The present invention relates to a sustained arc ignition system for an internal combustion engine, wherein there are provided an ignition power supply unit having a voltage transformer, a first voltage of a separate secondary winding thereof is applied to a primary winding of an ignition coil means, a second voltage of the separate secondary winding thereof is supplied to a secondary winding of said ignition coil means for storing an ignition energy, a low voltage driven by means of a switching element through an ignition signal for turning on the switching element and a microcomputer for controlling an ignition advance angle according to an engine operating condition.